Introduction In recent years, Ohio has enacted multiple laws that impact sexual and reproductive health. In February 2016, a new law came into effect, which prohibits the state from contracting health services with any organisation that performs or promotes abortion. This law blocks funding of organisations such as Planned Parenthood from receiving state funds for activities related to HIV and STD testing and sexual education.

Methods We are conducting a rigorous evaluation of the sexual and reproductive health-related consequences of the new law. In an ecologic analysis of state- and county-level data from Ohio for 2015 and 2016, we will compare trends in prevalence of HIV, chlamydia and gonorrhoea (all nationally notifiable conditions) before and after the implementation of the2016 law. We will examine trends by several characteristics, including sex, race/ethnicity, age, education level, insurance status (Ohio is a Medicaid-expansion state under the Affordable Care Act), sexual orientation, urban/rural residence, and other variables. To disentangle the effect of the law from secular trends in HIV/STD, we will compare Ohio’s outcomes to the same outcomes in nearby Illinois. Illinois has similar population characteristics to Ohio but does not have the same legislative environment impacting allocation of funds for reproductive health services.

Results Results will be available in summer 2017. In Ohio, we anticipate a decline in the number of HIV and STD tests performed in 2016 compared to 2015, and an increase in the prevalence of each disease in 2016 compared to 2015. We anticipate no meaningful changes in trends across years in Illinois.

Conclusion Multiple states across the United States are considering legislation similar to Ohio’s, to restrict the use of state and federal funding by clinical and community organisations that provide HIV/STD care alongside other sexual health services. Determining the HIV/STD-related impacts of such laws is critical to avoid putting men and women at higher risk of disease.